A minja is a midget ninja (mini ninja). Minjas are extremely small, fast and very dangerous. Santa Claus is a ninja and so are his elfs. It has however been debated whether the elfs are defined as minjas or not. For more info: www.askaninja.com

"And a minja, they can do some cool stuff that I really wish I could do. Like they'll throw a shuriken and then they'll jump on top of the very shuriken that they threw. It'll like hit you in the neck, then they'll punch you in the face."